The invention is an easy to open envelope that provides the user easy access to its contents, by virtue of a tape strip located along one side edge of the envelope body.
The stationery envelope has been an indispensable tool for communication throughout the last century, and, accordingly, much effort has been focused on making the design, manufacture and user-friendliness of this instrument more efficient and economical. In particular, several attempts have been made to improve the technical design of the envelope to allow the user easier access to the envelope contents, while at the same time reducing the risk of accidentally tearing the envelope body and damaging its contents or causing injury to the user.
The use of tear guides has been one means of providing simple, controlled access to the envelope contents. For example, U.S. Pat. No. 2,161,958 (MacDonald) discloses an envelope in which a cutting element is secured to the inner face of the rear section of the envelope. The cutting element, which may be a thin, twisted ribbon of cellophane, is secured between the upper and lower edges of the inner rear face of the envelope. In this position, according to the patent, the cutting element is in a concealed and inaccessible position within the envelope. Arced perforations near one or both corners of the rear section expose one or both ends of the cutting element at the back of the envelope, allowing the exposed ends to be grasped and pulled outward with a slitting motion to open the envelope.
U.S. Pat. No. 2,956,727 (Chevan) describes an envelope that includes a side strip secured to the inside of the front panel near the fold between the front and rear sections of the envelope. The portion of the strip that is between the front and rear sections has a pressure sensitive adhesive applied on either side, which permits the strip to function as a tearing member. The strip also allows functions as a re-sealing member that can be inserted between the open edges of the envelope to close it after it has been opened. An exposed portion of the strip containing no adhesive extends beyond the upper edge of the front panel, and when the envelope is sealed, this exposed portion is partially positioned beneath the upper sealing flap to provide an end or tab that can be lifted by the user and pulled to remove the strip and open the envelope.
U.S. Pat. No. 3,392,908 (Shelley) discloses a paper stationery envelope with a combination of corner guides and an internal tear strip of paper, plastic or cloth placed on the interior surface of the envelope along substantially the entire length of one or more edge folds of the envelope. The strip placed along the edge fold extends either over the entire length of the edge fold or close to the end of each edge, but, in any event, does not extend beyond the edges and there is no external indication of its presence.
This prior art, while recognizing the need for an envelope that can be torn open without detriment to the contents, has not solved the problem of providing an envelope with a reliable tear mechanism that can readily be identified by the user, and which is easy to manufacture on-line in a machine process for making envelopes.
It is therefore an object of the present invention to provide an easy-open envelope equipped with a tear mechanism that is visible to the user yet appropriately placed so as not to detract from other indicia located on the envelope, or to be accidentally snagged or otherwise engaged to permit unintentional opening of the envelope. In this respect, the invention is an envelope comprising a tape strip extending the length of one side edge of the front panel of the envelope and the corresponding region of the seal flap. Removal of the tear strip via a pull mechanism allows efficient removal of the side fold area of the envelope along a prefabricated opening while avoiding damage to the envelope contents.
In one aspect, therefore, the invention is an envelope comprising: a body formed from a front panel, the front panel having two opposing side edges, and a rear panel also having two opposing side edges; an overlapping seal flap which is foldably connected to the front panel; side flaps, each side flap being formed as an extension of a side edge of the front panel; and a tape strip affixed in contiguous, unbroken fashion along one side edge of the front panel and along the corresponding side edge of the seal flap; wherein the cut edge of the tape strip at the free edge of the seal flap is contiguous with and symmetrical in alignment to said free edge of the seal flap; a perforated region along the length of the seal flap adjacent to the tape strip; and a perforated region in the lower region of the front panel, said perforation being disposed at an angle in relation to the lower end of the tape strip; wherein a rip tab is formed by the aligned free edges of the tape strip and seal flap and said perforated region along the length of the seal flap.
The tape strip may be formed from any suitable adhesive, reinforcing material that is itself tear-resistant. For example, the tape strip may be formed form plastic tape or fiber-reinforced paper or plastic tape. Typically, the tape is adhesive-backed or is affixed to the envelope body with an adhesive. Desirably, the length of tape is not visible from the outside of the envelope. The tape strip may be formed of a transparent, colored, white or opaque material, and may optionally be printed, for example with a pattern or with text, such as advertising information.
Preferably, the tape strip is applied along one side of the front panel of an envelope blank, which has been scored and so divided into a front panel, rear panel, seal flap and side panels. The length of the tape strip may be extended beyond the length of the front panel and along the length of a corresponding region of the seal flap. Typically, before application of the tape strip to the seal flap, a gummy adhesive is applied to form a seal zone which, when adhered to the outside of the rear panel, forms the envelope closure. The tape strip may or may not overlap the seal zone, depending on the design and configuration of the seal flap. After the tape strip is applied to the blank, the corners of the seal flap are tapered by trimming the ends of the corners in an angular or curved fashion. This trimming step cuts through the excess paper substrate as well as the length of tape strip affixed to the excess substrate, and provides an identical cut line over the substrate material of the seal flap as well as the tape. After trimming, the upper free edge of the tape strip is contiguous with and symmetrically aligned to the upper free edge of the corresponding corner of the seal flap. A perforation may then be made along the region of tape affixed to the seal flap. The perforation may partially extend along the length of the tape strip, or it may extend along the entire length of the tape strip. In practice, the perforation permits the end of the tape, which is not itself covered by the gummy adhesive on the seal flap, to be lifted and torn away from the envelope body. The end of the tape strip thus forms a rip tab that allows easy initiation of the tearing action. In this respect, the seal flap and the attached rip tab so formed can be run through a stamp cancellation machine without being snagged or torn away by the equipment. An additional perforation may be included at or near the bottom of the front panel, to improve the tearing performance of the tape strip. This lower perforation may be angled between the side and lower edges of the front panel. The presence of both perforations, on the seal flap and on the lower front panel, allows the tape strip to be more precisely torn away from the envelope body such that the tear line is kept at or close to the edge of the tape strip itself.
To complete formation of the envelope, an adhesive is applied to the side flaps, after which the envelope throat is then formed by folding the rear panel to face the front panel, folding the side flaps inward, then folding and affixing the rear panel over the exteriors of the side panels.